June 1944 QST
articles are scanned and OCRed from old editions of the ARRL's QST magazine. Here is a list
of the QST articles I have already posted. All copyrights are hereby acknowledged.
was the name given to early walkie-talkies used in the field by
military communications troops. Having been written during World
War II, the author of this QST article just assumed that any reader
would be familiar with the WERS acronym - it stands for
War Emergency Radio Service
. Per the Wikipedia entry: "At
the start of the Second World War the United States Congress had
suspended all amateur radio activity throughout the country. WERS
was established by the Federal Communications Commission in June
1942 at the insistence of the American Radio Relay League. WERS
would remain in operation in through the end of the Second World
War in 1945. WERS was to provide communications in connection with
air raid protection, and communications during times of natural
disaster. WERS licenses were given to communities and not individuals.
One of the requirements for individuals to participate in the WERS
was to hold an Amateur radio license."
A Compact Light-Weight WERS Unit Operating from Dry Batteries
By Charles T. Haist. Jr., W6TWL. EX-W9EQL
application of units of the handie-talkie type to WERS work is very
practical in that they may be operated right at the scenes of incidents
or disaster, leaving the operator free to walk or move around and
still have one hand available to assist in other duties. Such low-power
units are intended primarily to be used in conjunction with a higher-powered
mobile unit which may be located several blocks away, parked in
a favorable spot which permits satisfactory communication with the
control center for the purpose of relaying messages.
necessary, however, surprising distances can be covered with handie-talkie
units when they are operated in the clear. Communications with control
center KMFY-1, with a signal report of R4/S4 at distances up to
ten miles, have been accomplished with the hand-portable shown in
the photographs. R5/S5 reports have been logged at distances of
up to three or four miles.
This unit is built along the
lines of some of those used by the armed forces. The complete transceiver
and its battery power supply, enclosed in an aluminum case as shown,
weighs but 3 7/8 pounds. The outside dimensions of the case are
only 2 5/8 X 2 3/4 X 11 inches. Circuit Details
The transceiver circuit, shown in Fig. 1, is more or less
conventional in most respects. It was drawn up around the type 1S4
tube, which is the secret of the set's compactness.
Two tubes of this type are used in the unit. One, with its screen
tied to the plate, is used as a triode oscillator and detector.
The other 1S4 is used as an audio amplifier and modulator.
Many have encountered trouble in getting the 1S4 to super-regenerate
on frequencies as high as 112 Mc. In this circuit this difficulty
was solved by placing a 0.005-μfd. condenser, C3, across the receiving
grid leak, R3.
* 750 Warfield Ave., Oakland 10, Calif.
The microphone is insulated from the aluminum case so that
it may be connected in series with the single headphone, P, for
side-tone transmitting. The headphone, which has an impedance of
about 100 ohms, was provided with an output transformer, T1
for proper impedance matching to the output of the 1S4. When transmitting,
the secondary is opened and the primary is used as a Heising modulation
for the audio amplifier or modulator is provided by operating the "B"
- below ground potential and using the voltage drop across R1
Regeneration is controlled by a simple variable series resistance,
, in the "B" + lead to the detector so that
an additional switch is not necessary to eliminate battery drain
when the set is turned off.
The change-over switch, S1
is a four-pole triple-throw rotary switch. In addition to the two
usual positions, a third position, labeled 0 in Fig. 1, is provided
where all battery circuits are open. The filament circuit is completed
when the switch is placed in either the receiving or the transmitting
The filament battery consists of two No. 3 flashlight
cells connected in parallel for longer life. They are held in the
case by spring clips. The plate battery is a 67 1/2-volt Minimax
or two 45-volt hearing-aid batteries in series. These batteries
are not too difficult to buy now, since stores are selling them
on the open market after the nominal installation date has passed.
One penlite cell provides adequate voltage for the microphone.
The case for the unit
is made of pieces of sheet aluminum fastened together with self-tapping
screws. The metal was given a "swirl" finish by applying
a spinning cork, held in the chuck of a drill press, after the aluminum
sheet had been smeared with a thin coating of a mixture of valve-grinding
compound and oil.
The microphone, mounted in the lower end
of the panel, and the single headphone at the top are from a Western
Electric handset in which the brass threads moulded in the handle
were cut off with a hacksaw to provide mountings. The regeneration
control is on the right side and the change-over switch on the left
side in a position convenient for one-hand operation.
two views of W6TWL's hand-portable transceiver show the arrangement
of controls. The left-side view shows the headphone. microphone,
and, on the side. the change-over switch. The right-side view shows
the regeneration control on the side and the tuning knob and scale
on the rear.
The batteries occupy the lower section of the
case, the "A" battery cells being mounted in clips at
the bottom and the "B" battery immediately above. The
penlite microphone battery is mounted in a clip on top of the headphone
The transceiver components consume the
remaining space at the top. The r.f. tube is mounted in an inverted
position in a polystyrene socket, while the audio tube socket is
fastened to a shelf at the left in the inside view of the unit.
The tank coil, L2
, is soldered directly to the terminals
of the tuning condenser, C5
, which is mounted immediately
below the antenna terminal.
The antenna is a quarter-wave
rod, 24 inches long, which plugs into a receptacle on top of the
case. It is coupled to the tank coil by a single turn of wire, L1
one end of which is grounded to the case. With this arrangement
transmission and reception seem to be good even with the antenna
at an angle or in a horizontal position.
has seen considerable successful service during the past few months.
The life of the batteries is very good despite their small size,
since the current drain on the filament battery is only 200 ma.
and the total "B" battery current is only 10 ma. when
receiving and 15 ma. when transmitting.
unit with the front cover removed. The miniature plate and filament
batteries occupy the lower portion of the case, while the r.f. and
audio components are fitted into the top section.
A Self-Contained Handie-Talkie
Fig. 1 - Circuit diagram of W6TWL's hand-portable WERS
- 0.001-μfd. midget mica.
- 0.003-μfd. midget mica.
- 0.005-μfd. midget
- 50-μfd. midget mica.
- 2-plate midget variable.
- 750 ohms, 1/2-watt
- 25,000 ohms, 1/2-watt carbon.
- 10 megohms, 1/2-watt carbon.
- 100,000-ohm potentiometer
- 1 turn No. 12, 1/2-inch
- 4 turns No. 12, 1/2-inch inside
- V.h.f. r.f. choke (Ohmite Z-0 or
M - Single-button carbon microphone (see
P - Single headphone, 100 ohms (see text).
- Four-pole three-position rotary switch.
to 100-ohm output transformer.
- Transceiver transformer.